This invention relates to a new fireplace assembly which is inserted into a conventional fireplace in a home.
Conventional fireplaces can provide heat but their principal purpose in recent times has been to provide the aesthetically pleasing appearance of a burning wood fire on a cold evening. However, the conventional fireplace can actually waste an enormous amount of heat. While a fire is burning, a substantial fraction of the heat generated passes directly up the chimney and is wasted. When the fire is extinguished, and even when the damper is closed, the fireplace can drain considerable heat from the room, which heat is produced by other furnace means such as an oil burner. If the fireplace damper is left open, the fireplace becomes a virtual heat sink and can waste tremendous amounts of heat.
Considering the recent energy crisis and the accompanying skyrocketing prices of heating oil and other petroleum products, it is clear that there is a need for more efficient fireplace operation. The present invention provides a fireplace assembly which fulfills that need and which also provides the aesthetically pleasing appearance of a conventional fireplace if desired.
A variety of approaches have been tried in the past in attempts to improve the heat transfer characteristics and thus the efficiency of fireplaces. Among these approaches has been the use of auxiliary forced air circulating systems such as that disclosed in U.S. Pat. No. 4,129,114, for example. Others have attempted to combine fireplaces with existing forced air furnace systems. Such approaches have not been entirely satisfactory.
Other approaches at improving heat transfer characterisistics have included various fin-type assemblies which have been designed into fireplaces such as that shown in U.S. Pat. No. 4,026,263 or have been incorporated in furnace-type assemblies which are placed into otherwise conventional fireplaces such as that shown in U.S. Pat. No. 4,026,264.
Fireplace shields have been provided such as disclosed in U.S. Pat. No. 4,010,730, presumably to improve heat radiation from the fireplace and, in this connection, various assemblies employing glass doors placed so as to enclose the fire are well known as shown in U.S. Pat. Nos. 4,058,107 and 4,129,114.
The present invention concerns what may be classified as a furnace-type assembly which may be installed directly into an existing, otherwise conventional fireplace. Furnace type assemblies consisting of a cast iron firebox having a door for inserting combustible fuel into a combustion chamber and connections to expel smoke up the chimney, the entire assembly being installed in a fireplace, are known and are commercially available from, for example, Elliott Stove Sales, Lynch, Md. Such prior fireplace assemblies contain none of the key features of the present invention, which features are set forth in full detail hereinbelow.